For the storage and transportation of fluid substances in bulk, containers in the form of a bag of flexible material disposed inside an outer casing of rigid or semi-rigid material are becoming increasingly popular. They have the advantage that the cleanliness or sterility of the inner bag, which receives the fluid substance, can be assured. Moreover, the material of the bag can form a reliable oxygen-impermeable barrier, which is important to prevent spoilage of food and other substances. Neither of the foregoing requirements could be so reliably achieved with previously used rigid drums, even where these were lined. With the new so-called "bag-in-box" type containers, of course, the bag can be disposed of and replaced after each trip so that problems of cleaning and possible contamination of the container interior do not arise.
Nowadays, products such as UHT milk, which require aseptic containers, are transported in the aforesaid type of bag-in-box container. Other products which require extremely hygenic and/or oxygen impermeable containers, such as fruit juices, tomato paste and juice, cosmetic ingredients, glues and resins, are also transported in this sort of container. It will be appreciated that such a container is suitable for pastes, powders and other granular material as well as liquids, all the foregoing being encompassed by the `fluid`.
The outer casing of such a container is generally made of metal and/or wood and/or corrugated board or other substantially rigid material and it may, for example, be about 1 m.times.1 m.times.1 m. This casing is used and re-used for transporting substances, often over very long distances and overseas. In contrast, the inner bag is generally made of multiple layers of sheet plastics, sometimes laminated or co-extruded with metalized foil, the layers being bonded, e.g. heat welded, together around their peripheral margins. As mentioned above, the bag is probably used only once and discarded.
The bag is not usually connected to the outer casing in any permanent, or even semi-permanent manner since it is designed to be placed into a casing, to unfold and expand in volume when filled with fluid so as to fill the interior of the casing, and subsequently to collapse again upon emptying so that it can thereafter be readily removed from the casing. The bag will either have a single inlet/outlet port through which it is filled and emptied, or two separate ports, namely an inlet port for filling and an outlet port for emptying. Moreover, in many cases the bag will also have a specially designated area or patch through which samples of fluid contained therein can be extracted by syringe, for example during customs inspections.
It is obviously important that the inlet/outlet port or respective ports and the aforesaid patch are correctly aligned with apertures in the outer casing so that access thereto is possible from the exterior of the container. In the case of an inlet port or a combined inlet/outlet port this is usually achieved simply by locating a member which defines the port in the appropriate aperture in the casing as the bag is placed in the casing. However, in the case of a separate outlet port and of a patch for sampling purposes it is necessary to carefully control the filling of the bag to try and bring the port and the patch to approximately the desired final location relative to the outer casing in which the bag is disposed. Careful control of the filling of the bag is also extremely important for another reason, namely to ensure that it unfolds and expands fully (i.e. without corners or lobes becoming trapped or compressed or air-filled) so as to accommodate the desired maximum quantity of fluid (e.g. 1 tonne) and prevent bag damage from distortion. It will thus be appreciated that the operation of filling the bag with the fluid to be stored and transported is absolutely critical to satisfactory use of this type of container.
Hitherto, the unfolding and expansion of the bag during the filling operation have required constant manual supervision and adjustment. This is time-consuming and greatly increases labour costs. Moreover if the supervisor is not skilled or is not vigilant, bag filling may still not be accomplished in a satisfactory manner.
It is an object of the present invention to provide a device which, in a bag-in-box container of the above-described type, will facilitate satisfactory unfolding and expansion of the bag during the filling operation so as to obviate the need for constant manual supervision.